481 THz "over the horizon" communications

Since my 2013 stroke, I have felt too wobbly to do field work. One of my great pleasures was trying optical communications over the horizon where I was astounded by what was possible, even though there was no sign of any light visible. Had I been fit, far further would have been possible.

See https://sites.google.com/view/g3xbm4/home/optical-nanowaves/over-the-horizon for some ideas. 

In many ways optical communications are easier than microwaves as all the gear (test gear and working kit) may be homemade at low cost.

The photo shows my first tentative steps in daylight along a road. Little did I realise what fun was to follow!